Packaged semiconductor dies, including memory chips, microprocessor chips, and imager chips, typically include one or more semiconductor dies mounted on a substrate and encased in a plastic protective covering or covered by a heat-conducting lid. The die can include functional features, such as memory cells, processor circuits, and/or imager devices, as well as bond pads electrically connected to the functional features. The bond pads can be electrically connected to terminals outside the protective covering to allow the die to be connected to higher level circuitry.
To avoid packaging a defective or “bad” die with a number of working or “good” dies (and thereby potentially rendering all of the dies in a package unusable), semiconductor dies may be tested before assembly to identify good and bad dies. Some testing approaches involve forming semi-permanent solder connections to contact pads on a semiconductor die, which may need to be removed before subsequent packaging and/or assembly steps. Traditional approaches to removing solder from semiconductor dies, such as vacuum suction, solder wicking and the like, can cause solder contamination or other damage to the semiconductor die. Accordingly, it is desirable to provide methods and structures for removing solder from semiconductor devices in a way that prevents damage to and/or contamination of the semiconductor devices.